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/*Copyright (c) 2011, Florent DEVILLE.                                      */
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#include "mlrMesh.h"

#include "CPrimTriangle.h"

//constructor
mlrMesh::mlrMesh() : _minAABB(0, 0, 0), _maxAABB(0, 0, 0), _triInteresected(0){}

//destructor
mlrMesh::~mlrMesh()
{
	for(vector<CPrimTriangle*>::iterator i = _triangles.begin(); i != _triangles.end(); i++)
	{
		if ((*i) != 0)
		{
			delete (*i);
			(*i) = 0;
		}
	}
}

//Check intersection between a ray and the primitive. If globalCoordinates is true, the ray is in global coordinates. If false, it is in view coordinates.
bool mlrMesh::intersect(const CRay& ray, float& dist, bool useGlobalCoordinates)
{
	//change the coordinate system
	CRay modRay;
	if (useGlobalCoordinates)
		globalToLocal(ray, modRay);
	else
		convertRayToLocalCoordinates(ray, modRay);

	for(vector<CPrimTriangle*>::iterator i = _triangles.begin(); i != _triangles.end(); i++)
	{
		bool res = (*i)->intersectLocalSpace(modRay, dist);
		if(res) 
		{
			_triInteresected = (*i);
			return true;
		}
	}

	_triInteresected = 0;
	return false;
}

//gives the normal in a point
void mlrMesh::computeNormal(const CRay& ray, float dist, CVector3f& normal) const
{
	if(_triInteresected == 0)
	{
		normal = CVector3f(0, 1, 0);
		return;
	}

	return _triInteresected->computeNormal(ray, dist, normal);
}

//add a triangle to the mesh
void mlrMesh::addTriangle(CPrimTriangle* newTriangle)
{
	_triangles.push_back(newTriangle);
}

//calculate the axis aligned bounding box
void mlrMesh::calculateAABB()
{
	_minAABB = _triangles[0]->getVertices()[0];
	_maxAABB = _minAABB;

	for(vector<CPrimTriangle*>::iterator i = _triangles.begin(); i != _triangles.end(); i++)
	{
		CVector3f* vertices = (*i)->getVertices();
		for(int c = 0; c < 3; c++)
		{
			if (vertices[c].x < _minAABB.x) vertices[c].x = _minAABB.x;
			if (vertices[c].y < _minAABB.y) vertices[c].y = _minAABB.y;
			if (vertices[c].z < _minAABB.z) vertices[c].z = _minAABB.z;

			if (vertices[c].x > _maxAABB.x) vertices[c].x = _maxAABB.x;
			if (vertices[c].y > _maxAABB.y) vertices[c].y = _maxAABB.y;
			if (vertices[c].z > _maxAABB.z) vertices[c].z = _maxAABB.z;
		}
	}
}